Monitoring Public Water Supply for a Variety of Pathogens

The simultaneous concentration and recovery of microbes in drinking water is important for responding to potential water-related events such as pathogen contamination or bioterrorism and could be a cost-effective technique for routine monitoring of drinking water quality. Scientists at the CDC have combined two techniques, ultrafiltration (UF) and insulator-based dielectrophoresis (iDEP) in series, to achieve significant concentration of microbes and pathogens for analysis. UF can concentrate a water sample =200X, depending on turbidity; if a secondary concentration step is applied, then a =25,000X can be achieved. Research has shown that UF can be an effective technique for simultaneously concentrating viruses, bacteria, and parasites in larger samples of drinking water. A second technique, the iDEP system, is known to be capable of capturing, concentrating, and separating microbes in very small water samples. The combination of UF with iDEP holds potential promise for allowing water utilities and associated industries to accurately detect low levels of pathogens in drinking water samples. This technology has the capability to separate live from non-viable microbes, thereby decreasing the chances of generating false-positive PCR results due to the presence of free nucleic acid or non-viable microbes.